Factors contributing to the separation of endodontic files

Cleaning and shaping of the root canal system is essential for successful endodontic treatment. However, despite improvements in file design and metal alloy, intracanal file separation is still a problematic incident and can occur without any visible signs or permanent deformation. Only a few studies have reported high success rates of fractured file removal using contemporary techniques. Conflicting results have been reported regarding the clinical significance of retaining separated files within root canals. An understanding of the mechanisms of, factors contributing to, file fracture is necessary to reduce the incidence of file separation within root canals. This article reviews the factors that are of utmost importance and in light of these, preventive procedures and measures are suggested.

[1]  E Schäfer,et al.  Relationship between design features of endodontic instruments and their properties. Part 3. Resistance to bending and fracture. , 2001, Journal of endodontics.

[2]  A Lussi,et al.  Probability of removing fractured instruments from root canals. , 2005, International endodontic journal.

[3]  G. Papadimitriou,et al.  Susceptibility to localized corrosion of stainless steel and NiTi endodontic instruments in irrigating solutions. , 2004, International endodontic journal.

[4]  G. Yared,et al.  Influence of rotational speed, torque and operator proficiency on failure of Greater Taper files. , 2002, International endodontic journal.

[5]  Yufeng Zheng,et al.  Comparative study of torsional and bending properties for six models of nickel-titanium root canal instruments with different cross-sections. , 2006, Journal of endodontics.

[6]  H. Messer,et al.  Complications Associated With Fractured File Removal Using An Ultrasonic Technique , 2005 .

[7]  E. Berutti,et al.  Influence of manual preflaring and torque on the failure rate of ProTaper rotary instruments. , 2004, Journal of endodontics.

[8]  Bradford R Johnson,et al.  A scanning electron microscopy evaluation of microfractures, deformation and separation in EndoSequence and Profile nickel-titanium rotary files using an extracted molar tooth model. , 2007, Journal of endodontics.

[9]  Geoff Bateman,et al.  Dynamic and cyclic fatigue of engine-driven rotary nickel-titanium endodontic instruments. , 1999 .

[10]  L. I. Grossman,et al.  Guidelines for the prevention of fracture of root canal instruments. , 1969, Oral surgery, oral medicine, and oral pathology.

[11]  H. Gerstein,et al.  An initial investigation of the bending and torsional properties of Nitinol root canal files. , 1988, Journal of endodontics.

[12]  Cyclic fatigue of nickel-titanium rotary instruments after clinical use with low- and high-torque endodontic motors. , 2001, Journal of endodontics.

[13]  J. Silvaggio,et al.  Effect of heat sterilization on the torsional properties of rotary nickel-titanium endodontic files. , 1997, Journal of endodontics.

[14]  G. Cantatore,et al.  The influence of a manual glide path on the separation rate of NiTi rotary instruments. , 2005, Journal of endodontics.

[15]  Proposed role of embedded dentin chips for the clinical failure of nickel-titanium rotary instruments. , 2004, Journal of endodontics.

[16]  Susan Wolcott,et al.  Separation incidence of protaper rotary instruments: a large cohort clinical evaluation. , 2006, Journal of endodontics.

[17]  P. Eleazer,et al.  A comparison of torque required to fracture rotary files with tips bound in simulated curved canal. , 2005, Journal of endodontics.

[18]  A C D Viana,et al.  Influence of sterilization on mechanical properties and fatigue resistance of nickel-titanium rotary endodontic instruments. , 2006, International endodontic journal.

[19]  G. Cheung,et al.  Defects in ProTaper S1 instruments after clinical use: fractographic examination. , 2005, International endodontic journal.

[20]  G. Yared,et al.  Influence of torque control motors and the operator's proficiency on ProTaper failures. , 2003, Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics.

[21]  Peter Parashos,et al.  Evaluation of an ultrasonic technique to remove fractured rotary nickel-titanium endodontic instruments from root canals: an experimental study. , 2003, Journal of endodontics.

[22]  E Mandel,et al.  Rotary Ni-Ti profile systems for preparing curved canals in resin blocks: influence of operator on instrument breakage. , 1999, International endodontic journal.

[23]  Harold H. Messer,et al.  Complications Associated with Fractured File Removal Using an Ultrasonic Technique , 2005 .

[24]  Peter Parashos,et al.  Factors influencing defects of rotary nickel-titanium endodontic instruments after clinical use. , 2004, Journal of endodontics.

[25]  N. Richards,et al.  Torsional properties of stainless-steel and nickel-titanium files after multiple autoclave sterilizations. , 2000, Journal of endodontics.

[26]  E. Lautenschlager,et al.  Corrosion in stainless-steel and nickel-titanium files. , 1999, Journal of endodontics.

[27]  J. Powers,et al.  The deterioration of rotary nickel-titanium files under controlled conditions. , 2002, Journal of endodontics.

[28]  Ya Shen,et al.  Factors associated with the removal of fractured NiTi instruments from root canal systems. , 2004, Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics.

[29]  J. Roulet.  Dynamic fracture of conventional endodontic instruments versus experimental files. , 1983, Journal of endodontics.

[30]  Effect of rotational speed on root canal preparation with Hero 642 rotary Ni-Ti instruments. , 2003, Journal of endodontics.

[31]  Ove A Peters,et al.  Analysis of torque and force with differently tapered rotary endodontic instruments in vitro. , 2005, Journal of Endodontics.

[32]  M. Günday,et al.  A comparative study of three different root canal curvature measurement techniques and measuring the canal access angle in curved canals. , 2005, Journal of endodontics.

[33]  C. Canalda-Sahli,et al.  The effect of sterilization on bending and torsional properties of K-files manufactured with different metallic alloys. , 1998, International endodontic journal.

[34]  E. Berutti,et al.  Influence of sodium hypochlorite on fracture properties and corrosion of ProTaper Rotary instruments. , 2006, International endodontic journal.

[35]  Mian K Iqbal,et al.  A retrospective clinical study of incidence of root canal instrument separation in an endodontics graduate program: a PennEndo database study. , 2006, Journal of endodontics.

[36]  H H Messer,et al.  Torque during canal instrumentation using rotary nickel-titanium files. , 2000, Journal of endodontics.

[37]  Helmut Walsch,et al.  The hybrid concept of nickel-titanium rotary instrumentation. , 2004, Dental clinics of North America.

[38]  John M Powers,et al.  SEM observations of nickel-titanium rotary endodontic instruments that fractured during clinical Use. , 2005, Journal of endodontics.

[39]  H. Steiman,et al.  Evaluation of single-use rotary nickel-titanium instruments. , 2003, Journal of endodontics.

[40]  H. Messer,et al.  The impact of instrument fracture on outcome of endodontic treatment , 2005, Journal of endodontics.

[41]  V T Himel,et al.  Torsional properties of nickel-titanium versus stainless steel endodontic files. , 1997, Journal of endodontics.

[42]  G. Yared,et al.  Cyclic fatigue of Profile rotary instruments after simulated clinical use. , 1999, International endodontic journal.

[43]  B. Martín,et al.  Factors influencing the fracture of nickel-titanium rotary instruments. , 2003, International endodontic journal.

[44]  B Peng,et al.  Defects in ProTaper S1 instruments after clinical use: longitudinal examination. , 2005, International endodontic journal.

[45]  G. Kuhn,et al.  Influence of structure on nickel-titanium endodontic instruments failure. , 2001, Journal of endodontics.

[46]  J. P. Pruett,et al.  Cyclic fatigue testing of nickel-titanium endodontic instruments. , 1997, Journal of endodontics.

[47]  P Machtou,et al.  Cyclic fatigue of ProFile rotary instruments after clinical use. , 2000, International endodontic journal.

[48]  Scanning electron microscope appearances of Lightspeed instruments used clinically: a pilot study. , 1998, International endodontic journal.

[49]  Bor-Shiunn Lee,et al.  Cyclic fatigue of endodontic nickel titanium rotary instruments: static and dynamic tests. , 2002, Journal of endodontics.

[50]  M Hülsmann,et al.  Influence of several factors on the success or failure of removal of fractured instruments from the root canal. , 1999, Endodontics & dental traumatology.